Komatsu A

References (5)

Title : An ancestral function of strigolactones as symbiotic rhizosphere signals - Kodama_2022_Nat.Commun_13_3974
Author(s) : Kodama K , Rich MK , Yoda A , Shimazaki S , Xie X , Akiyama K , Mizuno Y , Komatsu A , Luo Y , Suzuki H , Kameoka H , Libourel C , Keller J , Sakakibara K , Nishiyama T , Nakagawa T , Mashiguchi K , Uchida K , Yoneyama K , Tanaka Y , Yamaguchi S , Shimamura M , Delaux PM , Nomura T , Kyozuka J
Ref : Nat Commun , 13 :3974 , 2022
Abstract : In flowering plants, strigolactones (SLs) have dual functions as hormones that regulate growth and development, and as rhizosphere signaling molecules that induce symbiosis with arbuscular mycorrhizal (AM) fungi. Here, we report the identification of bryosymbiol (BSB), an SL from the bryophyte Marchantia paleacea. BSB is also found in vascular plants, indicating its origin in the common ancestor of land plants. BSB synthesis is enhanced at AM symbiosis permissive conditions and BSB deficient mutants are impaired in AM symbiosis. In contrast, the absence of BSB synthesis has little effect on the growth and gene expression. We show that the introduction of the SL receptor of Arabidopsis renders M. paleacea cells BSB-responsive. These results suggest that BSB is not perceived by M. paleacea cells due to the lack of cognate SL receptors. We propose that SLs originated as AM symbiosis-inducing rhizosphere signaling molecules and were later recruited as plant hormone.
ESTHER : Kodama_2022_Nat.Commun_13_3974
PubMedSearch : Kodama_2022_Nat.Commun_13_3974
PubMedID: 35803942

Title : KARRIKIN INSENSITIVE2 (KAI2)-dependent signaling pathway controls vegetative reproduction in Marchantia polymorpha - Komatsu_2022_Biorxiv__
Author(s) : Komatsu A , Kodama K , Mizuno Y , Fujibayashi M , Naramoto S , Kyozuka J
Ref : Biorxiv , : , 2022
Abstract : In vegetative reproduction of Marchantia polymorpha, propagules, called gemmae, are formed in gemma cups. Despite its significance for survival, control of gemma and gemma cup formation by environmental cues is not well understood. We show here that the number of gemmae formed in a gemma cup is a genetic trait. Gemma formation starts from the central region of the floor of the gemma cup, proceeds to the periphery, and terminates when the appropriate number of gemmae are initiated. The MpKARRIKIN INSENSITIVE2 (MpKAI2)-dependent signaling pathway promotes gemma cup formation and gemma initiation. The number of gemmae in a cup is controlled by modulating the ON/OFF switch of the KAI2-dependent signaling. Termination of the signaling results in the accumulation of MpSMXL, a suppressor protein. In the Mpsmxl mutants, gemma initiation continues, leading to the formation of a highly increased number of gemmae in a cup. Consistent with its function, the MpKAI2-dependent signaling pathway is active in gemma cups where gemmae initiate, as well as in the notch region of the mature gemma and midrib of the ventral side of the thallus. In this work, we also show that GEMMA CUP-ASSOCIATED MYB1 works downstream of this signaling pathway to promote gemma cup formation and gemma initiation. We also found that the availability of potassium affects gemma cup formation independently from the KAI2-dependent signaling pathway in M. polymorpha. We propose that the ancestral function of the KAI2-dependent signaling pathway may be to optimize vegetative reproduction by adapting to the environment.Competing Interest StatementThe authors have declared no competing interest.
ESTHER : Komatsu_2022_Biorxiv__
PubMedSearch : Komatsu_2022_Biorxiv__

Title : Desmethyl butenolides are optimal ligands for karrikin receptor proteins - Yao_2021_New.Phytol__
Author(s) : Yao J , Scaffidi A , Meng Y , Melville KT , Komatsu A , Khosla A , Nelson DC , Kyozuka J , Flematti GR , Waters MT
Ref : New Phytol , : , 2021
Abstract : Strigolactones and karrikins are butenolide molecules that regulate plant growth. They are perceived via the alpha/beta-hydrolase DWARF14 (D14) and its homologue KARRIKIN INSENSITIVE2 (KAI2), respectively. Plant-derived strigolactones have a butenolide ring with a methyl group that is essential for bioactivity. By contrast, karrikins are abiotic in origin, and the butenolide methyl group is non-essential. KAI2 is probably a receptor for an endogenous butenolide, but the identity of this compound remains unknown. Here we characterise the specificity of KAI2 towards differing butenolide ligands using genetic and biochemical approaches. We find that KAI2 proteins from multiple species are most sensitive to desmethyl butenolides that lack a methyl group. Desmethyl-GR24 and desmethyl-CN-debranone are active via KAI2 but not D14. They are more potent KAI2 agonists than their methyl-substituted reference compounds both in vitro and in plants. The preference of KAI2 for desmethyl butenolides is conserved in Selaginella moellendorffii and Marchantia polymorpha, suggesting that it is an ancient trait in land plant evolution. Our findings provide insight into the mechanistic basis for differential ligand perception by KAI2 and D14, and support the view that the endogenous substrates for KAI2 and D14 have distinct chemical structures and biosynthetic origins.
ESTHER : Yao_2021_New.Phytol__
PubMedSearch : Yao_2021_New.Phytol__
PubMedID: 33474738
Gene_locus related to this paper: arath-AtD14 , arath-KAI2.D14L

Title : Major components in the KARRIKIN INSENSITIVE2-ligand signaling pathway are conserved in the liverwort, Marchantia polymorpha - Mizuno_2020_Biorxiv__
Author(s) : Mizuno Y , Komatsu A , Shimazaki S , Xie X , Ishizaki K , Naramoto S , Kyozuka J
Ref : Biorxiv , 11.17.387852 : , 2020
Abstract : KARRIKIN INSENSITIVE2 (KAI2) was first identified in Arabidopsis thaliana as a receptor of karrikin, a smoke-derived germination stimulant. KAI2 is also considered a receptor of an unidentified endogenous molecule called the KAI2-ligand (KL). Upon KAI2 activation, signals are transmitted through degradation of D53/SMXL proteins via ubiquitination by a Skp-Cullin-F-box (SCF) E3 ubiquitin ligase complex. All components in the KL signaling pathway exist in the liverwort Marchantia polymorpha, namely MpKAI2A and MpKAI2B, MpMAX2 encoding the F-box protein, and MpSMXL, indicating that the signaling pathway became functional in the common ancestor of bryophytes and seed plants. Genetic analysis using knock-out mutants of these KL signaling genes, produced using the CRISPR system, indicated that MpKAI2A, MpMAX2 and MpSMXL act in the same genetic pathway and control early gemma growth. Introduction of MpSMXLd53, in which a domain required for degradation is mutated, into wild-type plants caused phenotypes resembling those of the Mpkai2a and Mpmax2 mutants. In addition, Citrine fluorescence was detected in tobacco cells transiently transformed with the 35S:MpSMXL-Citrine gene construct and treated with MG132, a proteasome inhibitor. On the other hand, introduction of 35S:MpSMXLd53-Citrine conferred Citrine fluorescence without MG132 treatment. These findings imply that MpSMXL is subjected to degradation, and that degradation of MpSMXL is crucial for KL signaling in M. polymorpha. We also showed that MpSMXL is negatively regulated by KL signaling. Taken together, this study demonstrates that basic mechanisms in the KL signaling pathway are conserved in M. polymorpha.
ESTHER : Mizuno_2020_Biorxiv__
PubMedSearch : Mizuno_2020_Biorxiv__

Title : Quantification of plasma exosome is a potential prognostic marker for esophageal squamous cell carcinoma - Matsumoto_2016_Oncol.Rep_36_2535
Author(s) : Matsumoto Y , Kano M , Akutsu Y , Hanari N , Hoshino I , Murakami K , Usui A , Suito H , Takahashi M , Otsuka R , Xin H , Komatsu A , Iida K , Matsubara H
Ref : Oncol Rep , 36 :2535 , 2016
Abstract : Exosomes play important roles in cancer progression. Although its contents (e.g., proteins and microRNAs) have been focused on in cancer research, particularly as potential diagnostic markers, the exosome behavior and methods for exosome quantification remain unclear. In the present study, we analyzed the tumor-derived exosome behavior and assessed the quantification of exosomes in patient plasma as a biomarker for esophageal squamous cell carcinoma (ESCC). A CD63-GFP expressing human ESCC cell line (TE2-CD63-GFP) was made by transfection, and mouse subcutaneous tumor models were established. Fluorescence imaging was performed on tumors and plasma exosomes harvested from mice. GFP-positive small vesicles were confirmed in the plasma obtained from TE2-CD63-GFP tumor-bearing mice. Patient plasma was collected in Chiba University Hospital (n=86). Exosomes were extracted from 100 microl of the plasma and quantified by acetylcholinesterase (AChE) activity. The relationship between exosome quantification and the patient clinical characteristics was assessed. The quantification of exosomes isolated from the patient plasma revealed that esophageal cancer patients (n=66) expressed higher exosome levels than non-malignant patients (n=20) (P=0.0002). Although there was no correlation between the tumor progression and the exosome levels, exosome number was the independent prognostic marker and low levels of exosome predicted a poor prognosis (P=0.03). In conclusion, exosome levels may be useful as an independent prognostic factor for ESCC patients.
ESTHER : Matsumoto_2016_Oncol.Rep_36_2535
PubMedSearch : Matsumoto_2016_Oncol.Rep_36_2535
PubMedID: 27599779